The inner wall of the piping system of the Sekisui cleanpvc ultra pure water pipeline in Japan is as flat as a mirror. The resistivity is 1/20 of that of the ordinary PVC pipeline. The decline rate of the resistivity of the ultra pure water during shutdown is 1/30 of that of the ordinary PVC pipeline, The TOC precipitation of the pipeline itself is very small. It is the most ideal clean pipe fitting for the transmission of 18m Ω ultra pure water in electronic industry, semiconductor industry, photoelectric display industry and solar photovoltaic industry.